Bugfixes:
- Made the HDD-Audio-Code silence buffers in advance before doing a seek
operation. Stops noise on end of file or decoding errors.
- Corrected hanging of audio decoding loop bug on some MP3-files.
(you had to close blender and restart)
- Made preseeking code not seek before beginning of file.
seqaudio:
- made some "local globals" static.
Problems remaining: VBR-MP3-length isn't detected correctly so the
displayed sequence strip is too long...